Measurements of flow parameters and decompression wave speed following rupture of rich gas pipelines,and comparison with GASDECOM

Measurements of flow parameters and decompression wave speeds in a conventional gas mixture and two other rich gas mixtures following rupture of a high-pressure pipe have been conducted. A test rig, consisting of a stainless steel expansion tube (internal diameter ∼50 mm), has been used to give a length to diameter ratio of 3440 representing a long section of a pipeline. Pressure– and temperature–time traces obtained with high-frequency response transducers have been collected at various locations close to rupture and along the length of the tube. Tests were conducted at three pressure levels: 10, 14 and 20 MPa and at temperatures as low as −25 °C. Results indicate good agreement between measured and predicted decompression wave speed by GASDECOM. Additionally, gas temperature–time traces were also measured at different locations along the expansion tube. Since the temperature probes are not as fast in their response, a technique has been developed to reconcile the actual gas temperature from the measured data. The paper presents example results for lean, medium and rich gas mixtures at different initial conditions.